First reported by Kotaku, Pepsi Special contains indigestible dextrin, which is a dietary fiber supplement. The dextrin makes it difficult for the body to absorb fat, says Kotoku. Pepsi worked with Suntory, the bottler and distributor, to make sure the newest product doesn’t have a strong dextrin aftertaste.

While it may not sound too safe, the drink was approved by the government as a “food for specified health uses.” That designation stems from a 2006 study from Japan, which tested rats that were fed dextrin and fat. The rats who ate both dextrin and fat ingested less fat than those who ate just fat.